Ultraviolet light, despite being something that we know exists, even having an impact upon our physical bodies, is part of the spectrum of light we can't see unaided. This idea — that of a form of light that is present but not always apparent — is at the core of Ultraviolet, the sixth studio album from respected sludge experimenters Kylesa. Based in Savannah, GA, Kylesa have drawn from influences as diverse as doom and psychedelia to sculpt their sound, which is driven by powerful, aggressive drumming (they've been known to record and perform live with two percussionists playing simultaneously) and a smoky, syrup-thick guitar tone.

What sets Ultraviolet apart is the emotional authenticity and vulnerability of the record. While the music has become denser and chillier, with vocalist/guitarist Phillip Cope also commanding the recording and production, introducing darker keys and other electronic elements into the mix, the subject matter has ventured inwards, becoming more difficult and personal. Laura Pleasants is now the primary vocalist, taking on a much larger singing role on this record, and her warm, plaintive vocals serve as an entry point in the densely knit and sometimes alienating musical landscape. Her voice drips loss and yearning in "Long Gone" and drawls almost playful in "Quicksand" as she describes her mouth filling with blood. Rich and vibrant musically while raw and emotive lyrically, Ultraviolet is Kylesa's highest achievement to date.